<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>11_css选择器</title>
    <style>
        /* 标签选择器一般设置一些通用样式 */
        *, html, body {
            margin: 0;
            padding: 0
        }
      a {
        text-decoration: none;
      }
      ul, li {
        list-style: none;
      }
      #title {
        color: red
     }
     /* css权重 当寻找路径越精确 权重越高 id选择器 最高 */
     .container .title {
        font-size: 30px;
        color: blue;
     }
     .title {
        color: pink;
     }
    
     #title:hover {
       color: blue;
       font-weight: bolder;
     }
     .btn {
        background-color: brown;
        color: white;
     }
     .btn:hover {
        font-size: 20px;
     }
     .btn:active {
        background-color: rgb(104, 148, 167);
     }
    </style>
</head>
<body>
    <div class="container">
        <div>
            <span class="title">第二层级</span>
        </div>
        <span id="title" class="title">第一层级</span>

    </div>
    <ul>
        <li>123</li>
        <li>456</li>
        <li>789</li>
    </ul>
    <a href="">新浪</a>

    <span class="title">456</span>

    <span>789</span>
    <button class="btn">测试悬停和激活</button>
</body>
</html>